CODEWITHSUNDEEP
javascriptnode.jswebsocket
oystersauce
oystersauce

Reputation: 53

Node-js: Not receiving events after websocket reconnect

my node-js application uses the bitfinex-api-node npm package to establish a websocket connection to receive data from the Bitfinex crypto-currency exchange.

Unfortunately, the connections silently breaks after some hours and the app stops receiving data over the websocket. This seems to be a known issue, maybe a bug of the bitfinex-api-module.

Now, I'm trying to "manually" reconnect by first connecting the websocket and subscribing to some candle data. Then the websocket.close() function gets called to simulate a connection error at runtime. In the on close function I set another timeout and try to create a new BFX() object and open() it but .on(open) never gets called.

=> I must be doing something wrong. Is there a mistake in my logic? Is there a better way to reconnect?

The following code works, just copy paste it and run to see for yourself. I am very thankful for any hints or tips.

const BFX = require('bitfinex-api-node');

//websocket
const opts = {
  manageCandles: true, 
  transform: true,
  API_KEY: 'hidden',
  API_SECRET: 'hidden',
  ws: {
    autoReconnect: true,
    seqAudit: true,
    packetWDDelay: 10 * 1000
  }
};
var websocket = new BFX().ws(2, opts);

websocket.on('open', () => {
    //websocket.auth.bind(websocket)
    console.log('.on(open) called');
    websocket.subscribeCandles('trade:5m:tBTCUSD')
});

websocket.on('close', ()=>{
    console.log('.on(close) called');
    setTimeout(function() { 
        websocket = new BFX().ws(2, opts);
        websocket.open();
    }, 10000);
});

websocket.onCandle({key: 'trade:5m:tBTCUSD'},(candles) => { 
    console.log(candles[0]);
})

websocket.open();

// this closes the connection after 20 seconds 
//after start for debugging purposes:
setTimeout(function() {         
        websocket.close();
    }, 10000);

Upvotes: 4

Views: 885

Answers (1)

Yury Fedorov
Yury Fedorov

Reputation: 14928

The problem is that you don't attach any listeners to a new instance of websocket, when a previous one is closed:

websocket.on('close', ()=>{
    console.log('.on(close) called');
    setTimeout(function() { 
        // this creates a new instance without listeners
        websocket = new BFX().ws(2, opts);
        websocket.open();
    }, 10000);
});

While when you initialize the websocket for the first time, you add them:

websocket.on('open', /* code */);
websocket.onCandle(/* code */);

To resolve the issue, I suggest writing a function that creates and configures a new instance of websocket:

function createWebsocket() {
    const websocket = new BFX().ws(2, opts);
    websocket.on('open', /* code */);
    websocket.onCandle(/* code */);
    websocket.open();
}

And calling it in on('close'):

websocket.on('close', ()=>{
    console.log('.on(close) called');
    setTimeout(createWebsocket, 10000);
});

Upvotes: 1

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